The present invention relates to a method of managing a life of a storage medium for storing data, storage device, storage system and storage medium, and more particularly to a storage medium life management method, storage device, storage system and storage medium for determining the life of a storage medium pursuant to utilizing a removable storage medium.
Storage media capable of being loaded into and unloaded from storage drives are used widely. A memory cartridge is a typical such storage medium. The memory cartridge has a structure formed by housing a data-storing storage medium in a cartridge case. Memory cartridges such as this include magnetic disk cartridges, optical disk cartridges, magneto-optical disk cartridges, and magnetic tape cartridges. A memory cartridge is loaded into a drive, and then the drive head accesses the storage medium in the memory cartridge to perform read/write operations. After read/write operation, the memory cartridge is ejected from the drive.
This storage medium has a life. For a storage medium whose life has expired, there is the danger that data will not be able to be read. For this reason, technology for managing the life of a storage medium has become necessary.
As methods for managing the life of this storage medium, the following prior methods have been known.
(1) A drive writes the utilization start time into a memory cartridge, and manages the life of the memory cartridge by the elapsed time from the utilization start time.
(2) A drive writes the number of loads into a memory cartridge, reads out the number of loads, and manages the life of the memory cartridge according to the number of loads.
However, the problem has been that a method for managing life by the time that elapses from a utilization start time and a method for managing life by the number of loads do not necessarily show the deterioration of the storage medium or the deterioration of the data on the storage medium. That is, in addition to performance deterioration resulting from age deterioration of the storage medium itself, the life of a storage medium also deteriorates as a result of the storage medium being used. For example, the surface of a magnetic tape is worn by coming in contact with a magnetic head, causing performance to deteriorate. Also, dust and the like adhere to the surface of the tape, causing performance to deteriorate. Phenomena such as this also occur for disks and other media besides tape.
For the prior art, the life of a storage medium was determined to be over when a specified utilization period elapsed even if only one data-write operation had been performed. Or, the life of a storage medium was determined to be over when a specified number of loads had been exceeded even though only a small quantity of data was accessed on the storage medium at each load. In cases such as these, there was practically no deterioration of the storage medium. Thus, the replacement of the storage medium had to be carried out despite the fact that the storage medium had not deteriorated. This was a problem because it wastefully increased the costs of storage media for users.
By contrast, when the utilization frequency of a storage medium is extremely high, or when there is a large volume of input/output data at each load, the medium deteriorates prior to a specified value for a utilization period or number of loads. Consequently, the problem was that loss of user data and other such problems occurred before the specified value for a utilization period or number of loads.
Furthermore, the results of a determination of the life of a storage medium were only displayed on the indicator of the storage device thereof, and were not communicated to the management system of this storage device. An operator had to look at the indicator content of a storage device to manage the life of a storage medium. Thus, the problem was that a host or other management system could not manage the life. For automated storage systems such as a library system in particular, managing the life of a storage medium was really difficult.
Therefore, an object of the present invention is to provide a storage medium life management method, storage device, storage system, and storage medium for determining life based on the deterioration of the storage medium.
Further, an object of the present invention is to provide a storage medium life management method, storage device, storage system, and storage medium for preventing the wasteful replacement of a storage medium and loss of data.
Furthermore, an object of the present invention is to provide a storage medium life management method, storage device, storage system, and storage medium for collecting management information, which indicates life based on the deterioration of a storage medium.
Furthermore, an object of the present invention is to provide a storage medium life management method, storage device, storage system, and storage medium for automatically determining life according to the deterioration of a storage medium.
Furthermore, an object of the present invention is to provide a storage medium life management method, storage device, storage system, and storage medium for determining life according to the deterioration of a storage medium for an automated storage system as well.
The present invention is a storage device for accessing a loaded storage medium, and reading and writing data to and from the above-mentioned storage medium. And the method for managing the life of this storage medium comprises the steps of reading medium life management information from the above-mentioned loaded storage medium; detecting an operating condition of at least one of the reading and the writing of data in the above-mentioned storage medium, and updating the above-mentioned medium life management information in accordance with results of such detection; and writing the above-mentioned updated medium life management information to the above-mentioned storage medium upon unloading the storage medium.
In the present invention, based on the experience that the life of a storage medium is related to actual read/write operations, the operating condition of at least one of the reading and the writing of a storage medium is detected, and the detected result is utilized in the information for managing the life of a medium. Then, by storing this medium life management information on the storage medium, reading it out at loading time, updating it, and then rewriting it to the storage medium, a history of management information is retained on the storage medium. Because operating conditions, such as operating time, number of data errors and number of servo errors at read/write are treated as management information, the deterioration of a storage medium can be accurately detected. Thus, it is possible to prevent wasteful storage medium replacement and data loss.
Another aspect of the present invention further comprises a step for reporting the above-mentioned medium life management information to a management device for managing the life of the above-mentioned storage medium. Thus, a determination of life becomes possible by a management device that is separate from a storage device, making it easy for an operator to confirm the life of a storage medium.
Another aspect of the present invention further comprises a step for analyzing the above-mentioned medium life management information and determining the life of the above-mentioned storage medium. Because the life of a storage medium is also determined, this determination can be displayed on a storage device indicator or a management device, and an operator can be prompted to replace a storage medium.
Another aspect of the present invention further comprises a step for setting determination parameters for the above-mentioned determination step. Since it is possible to change a determination condition, a life determination can be executed in accordance with a user request.
Another aspect of the present invention further comprises a step for reporting the above-mentioned determination results to a management device for managing the life of the above-mentioned storage medium. Because the determination results are reported to a management device that is separate from the storage device, the management device can manage the life of a storage medium. For this reason, managing the life of a storage medium can be automated by an automatic storage system using the management device.
In another aspect of the present invention, the above-mentioned updating step comprises steps for detecting a plurality of states of at least one of the reading and the writing of data in the above-mentioned storage medium, and for updating the above-mentioned medium life management information in accordance with each of the above-mentioned plurality of states.
Since a plurality of states are detected and treated as management information, the deterioration of a storage medium can be determined from a variety of perspectives.
Another aspect of the present invention also has steps for analyzing each of the plurality of states of the above-mentioned medium life management information, and for determining the life of the above-mentioned storage medium from the results of each analysis. Because a determination is made by combining the results of respective analyses of a plurality of states, a variety of factors can be analyzed, making possible an accurate life determination.
In another aspect of the present invention, the above-mentioned determination step comprises steps for determining the life of the above-mentioned storage medium based on the above-mentioned respective analyses results, and detecting the reason for the above-mentioned determination. Since the reason for a determination is also detected, deterioration factors can be communicated to an operator, and the operator can make an accurate decision about replacement.
In another aspect of the present invention, the above-mentioned updating step comprises steps for detecting an operating quantity of at least one of the reading and the writing of data when data is read or written from/to the above-mentioned storage medium, and for updating the above-mentioned medium life management information according to results of such detection. Since operating quantities such as operating time or number of operating paths, constitute medium deterioration factors, a determination of medium life is made by detecting these factors.
In another aspect of the present invention, the above-mentioned updating step comprises steps for detecting data error states of at least one of the reading and the writing of data when data is read or written from/to the above-mentioned storage medium, and for updating the above-mentioned medium life management information according to the detection results. Since data error states, such as the number of data errors, directly affect the read/write performance of a storage medium, a determination can be made regarding the deterioration of a storage medium regardless of the elapsed time.
In another aspect of the present invention, the above-mentioned updating step comprises steps for detecting head servo error sate of at least one of the reading and the writing of the above-mentioned storage medium data, and for updating the above-mentioned medium life management information according to the detection results. When there are frequent error states of a servo controller for positioning a head on a storage medium, it is possible to make a determination that the storage medium on which the servo information is stored has deteriorated, and it is for this reason that servo error states are used as management information.
In storage system of the present invention, the storage device is constituted by a library system having a storage drive that accesses a loaded storage medium, and reads/writes data from/to the above-mentioned storage medium, and an accessor for loading a desired storage medium into the above-mentioned storage drive, and removing the above-mentioned storage medium from the above-mentioned storage drive. In a library system, in which an accessor performs the handling of a storage medium, because a storage medium is moved around in a closed space inside the device, it is difficult for an operator to see a storage medium and make a determination as to its life. Thus, the storage system of the present invention is constituted such that, by reporting medium life management information to a management device of the library system, the life of a storage medium inside the library system is managed by the management device. For this reason, the life of a storage medium can be easily managed even in an automated storage system just like in the library system, making it possible to incorporate the present invention in an automated system.